1. Field of the Invention
The present invention relates to a working vehicle such as a tractor, which is provided with an engine at the front portion thereof, and the working vehicle of which an implement is attachable to the front or rear portion thereof.
2. Related art of the Invention
A tractor described in each patent document of Japanese Patent Application Laid-Open Nos. 2007-8317 and 2006-304691 is known as a conventional example of a working vehicle of which a front loader, as an example of the implement, is attached to a front portion.
This conventional tractor is a four-wheel drive tractor which is driven by front wheels and rear wheels, and a driving force generating portion covering an engine with an engine hood is disposed on the front portion of the tractor. A operator's seat is disposed between the left and right rear wheels, and a roll-over protective structure with a top horizontal bar and a pair of vertical support columns is provided vertically behind the operator's seat.
As shown in FIG. 19, in the case of such conventional tractor, a radiator 8, the engine (not illustrated) and the various machine components that are associated with the engine are accommodated in the engine compartment R that is formed by the engine hood 4.
A frame structure 10, which is made from aluminum die-casting, serving as the rear wall of the driving force generating portion is provided vertically at the rear portion of the engine compartment R, and a panel cover 11 and a center cover 12 which covers a whole of the structure below the panel cover 11 are attached to the frame structure 10.
An instrument panel and various switches (not illustrated) are installed in the panel cover 11, and a rear side ventilation opening 14 whose structure blocks out dust is formed in the center cover 12. The outside air which has been introduced through the rear side ventilation opening 14 is sucked in by a radiator fan (not illustrated) and guided to the radiator 8, and then the air flows forward in the engine compartment R, and as a result, the heat within the engine compartment R is discharged to the outside through ventilation openings (not illustrated) in the front face and lateral fore portions of the engine hood 4.
As shown in FIG. 19, a valve unit 39, which is connected to a lift cylinder and a bucket cylinder (not illustrated) that move a front loader and a bucket (not illustrated), is disposed in the space which is formed at the lower portion of the frame structure 10. An operation lever 47 for operating the valve unit 39 is disposed at the upper right side of the frame structure 10, and further, a battery 31 is located at the intermediate position in the vertical direction of the frame structure 10.
The valve unit 39 is furnished with two spools 48 and 49 (see FIG. 19) that can slide to a right and left direction and that project to the right side of the vehicle body, where the one spool 48 can be slid among three positions to select an extension state, a retraction state, or an intermediate stationary state of the lift cylinder (not illustrated), and the other spool 49 can be slid among three positions to select an extension state, a retraction, state, or an intermediate stationary state of the bucket cylinder (not illustrated).
The operation lever 47 and the two spools 48 and 49 (see FIG. 19) are operatively connected by a link mechanism 50 which includes a lift rod 57 and a tilt rod 61. When the operator moves the operation lever 47 to a lengthwise direction or a right-left side direction of the vehicle body, the lift cylinder or the bucket cylinder is actuated, and thereby, the rising and lowering operation of the front loader or the rollback and dumping operation of the bucket is performed.
The lift rod 57, the tilt rod 61, and the valve unit 39 are covered and hidden by the center cover 12, and the outside air that is sucked in through the rear side ventilation openings 14 of the center cover 12 and circulated toward the radiator 8 cools the valve unit 39 and the battery 31.